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We study constraints on new physics from Higgs production at the LHC in the context of an effective field theory (EFT), focusing on Higgs searches in $HV$ ($V=W,Z$) associated production which are particularly sensitive to the high-energy…

High Energy Physics - Phenomenology · Physics 2015-04-01 Anke Biekoetter , Alexander Knochel , Michael Kraemer , Da Liu , Francesco Riva

In this paper we present a global fit of beyond the Standard Model (BSM) dimension six operators relevant to the top quark sector to currently available data. Experimental measurements include parton-level top-pair and single top production…

High Energy Physics - Phenomenology · Physics 2015-12-02 Andy Buckley , Christoph Englert , James Ferrando , David J. Miller , Liam Moore , Michael Russell , Chris D. White

The shift in focus towards searches for physics beyond the Standard Model (SM) employing model-independent Effective Field Theory (EFT) methods necessitates a rigorous approach to matching to guarantee the validity of the obtained results…

High Energy Physics - Phenomenology · Physics 2023-03-29 Upalaparna Banerjee , Joydeep Chakrabortty , Christoph Englert , Shakeel Ur Rahaman , Michael Spannowsky

We perform a comprehensive study of the Higgs couplings, gauge-boson couplings to fermions and triple gauge boson vertices. We work in the framework of effective theories including the effects of the dimension-six operators contributing to…

High Energy Physics - Phenomenology · Physics 2019-02-13 Eduardo da Silva Almeida , Alexandre Alves , N. Rosa Agostinho , Oscar J. P. Éboli , M. C. Gonzalez-Garcia

In the Standard Model and many of its extensions, it is well known that all of the observables associated with the rare decays $b\to s\gamma$ and $b\to s\ell^+\ell^-$ can be expressed in terms of the three Wilson coefficients,…

High Energy Physics - Phenomenology · Physics 2014-11-17 Thomas G. Rizzo

We calculate the one- and two-loop matching corrections in the Standard Model effective field theory (SMEFT) that impact electroweak precision measurements and flavour physics observables, focusing on the contributions of third-generation…

High Energy Physics - Phenomenology · Physics 2025-01-17 Ulrich Haisch , Luc Schnell

We perform an updated fit to LHC Higgs data and LEP electroweak precision tests in the framework of the Standard Model Effective Field Theory (SMEFT). We assume a generic structure of the SMEFT operators without imposing any flavour…

High Energy Physics - Phenomenology · Physics 2020-05-20 Adam Falkowski , David Straub

We study the dimension-six SMEFT four-lepton operators in the $\mu$--$\tau$ sector. These operators control both charged-lepton scattering and neutrino self-interactions, the latter being weakly constrained by direct laboratory probes…

High Energy Physics - Phenomenology · Physics 2026-05-01 Aadarsh Singh , G. D'Ambrosio , Sudhir K. Vempati

In models of electroweak symmetry breaking in which the SM fermions get their masses by mixing with composite states, it is natural to expect the top quark to show properties of compositeness. We study the phenomenological viability of…

High Energy Physics - Phenomenology · Physics 2010-03-19 Alex Pomarol , Javi Serra

The extraction of the Cabibbo-Kobayashi-Maskawa (CKM) matrix from flavour observables can be affected by physics beyond the Standard Model (SM). We provide a general roadmap to take this into account, which we apply to the case of the…

High Energy Physics - Phenomenology · Physics 2019-06-05 Sébastien Descotes-Genon , Adam Falkowski , Marco Fedele , Martín González-Alonso , Javier Virto

New physics can manifest itself by an appreciable increase of the decay rate of top quarks in rare flavour-changing final states. Exploiting the large top quark production rate at the LHC, we bound four-fermion operators contributing to…

High Energy Physics - Phenomenology · Physics 2019-05-01 Mikael Chala , Jose Santiago , Michael Spannowsky

We perform global fits within Standard Model Effective Field Theory (SMEFT) combining top-quark pair production processes and decay with $b\rightarrow s$ flavor changing neutral current transitions and $Z \to b \bar b$ in three stages:…

High Energy Physics - Phenomenology · Physics 2021-06-16 Stefan Bißmann , Cornelius Grunwald , Gudrun Hiller , Kevin Kröninger

We perform a model-independent analysis of $|\Delta b|=|\Delta d|=1$ processes to test the standard model and probe flavor patterns of new physics. Constraints on Wilson coefficients are obtained from global fits to $B^+ \to \pi^+…

High Energy Physics - Phenomenology · Physics 2023-06-07 Rigo Bause , Hector Gisbert , Marcel Golz , Gudrun Hiller

The study of the top quark's properties is an important part of the LHC programme. In earlier work, we have studied the rare decay $t \to b \bar b c$, using effective operators to capture the effects of physics beyond the Standard Model.…

High Energy Physics - Phenomenology · Physics 2018-09-05 Pratishruti Saha , Ken Kiers , Alejandro Szynkman

We implement electroweak renormalisation schemes involving the effective weak mixing angle to NLO in Standard Model Effective Field Theory (SMEFT). After developing the necessary theoretical machinery, we analyse a select set of electroweak…

High Energy Physics - Phenomenology · Physics 2023-12-15 Anke Biekötter , Benjamin D. Pecjak , Tommy Smith

Extending the Standard Model with higher-dimensional operators in an effective-field-theory (EFT) approach provides a systematic framework to study new-physics (NP) effects from a bottom-up perspective, as long as the NP scale is…

High Energy Physics - Phenomenology · Physics 2020-01-29 Marzia Bordone , Oscar Catà , Thorsten Feldmann

At energies below the electroweak scale, baryon number $B$ and lepton number $L$ violating processes are of significant importance in identifying the nature of UV extensions of the Standard Model. The imprint of UV theories on low-energy…

High Energy Physics - Phenomenology · Physics 2021-10-15 Joydeep Chakrabortty , Suraj Prakash , Shakeel Ur Rahaman , Michael Spannowsky

We investigate new-physics contributions to $b\to s \ell\ell$ transitions in the context of an effective field theory extension of the Standard Model, including operator mixing at one loop. We identify the few scenarios where a single…

High Energy Physics - Phenomenology · Physics 2020-02-19 Rupert Coy , Michele Frigerio , Federico Mescia , Olcyr Sumensari

Measurements at B factories have provided important constraints on new physics in several rare processes involving the B meson. New Physics, if present in the b quark sector may also affect the top sector. In an effective Lagrangian…

High Energy Physics - Phenomenology · Physics 2010-04-23 Alakabha Datta , Murugeswaran Duraisamy

We discuss the impact of many previously neglected effects of higher dimensional operators when fitting to Electroweak Precision data (EWPD) in the Standard Model Effective Field Theory (SMEFT). We calculate the general case of $2…

High Energy Physics - Phenomenology · Physics 2017-07-18 Laure Berthier , Michael Trott